Method of making skis



March 14, 1950 H. 1.. PETTERSSON ETAL 2,500,564

METHOD OF MAKING sxxs Filed Sept. 26, 1946 IN VENTORS HENRY Luow/aPsrrsfisso 61/541 Mwv Sam/05R.

fly/ ATTORNEYS 7 Patented Mar. 14,. 1950 METHOD OF MAKING SKIS HenryLudwig Pettersson, Sundsvall, and Sven Ivan Selanger, ()rnskoldsvik,Sweden Application September 26, 1945, Serial No. 618,668 In SwedenOctober 5, 1943 Section 1, Public Law 690, August 8, 1946 Patent expiresOctober 5, 1963 2 Claims: (01. 280-11.13)

' The present invention refers to a method of making skis with a tensionare as permanent as possible by the production of arcuate blocks, out ofwhich blanks are sawn, which are then worked into a ski.

The invention is illustrated in the accompanying drawing, wherein Fig. 1is a perspective view of a block which for the sake of clearness isshown with an exaggerated width. Fig. 2 is a perspective view of aspecially formed board sawn out of said block, and the upper part ofFig. 3 is a perspective view illustrating a block obtained by workingthe block according to Fig. 1, and the lower part of Fig. 3 shows aboard sawn out of the block, this board being intended to form a portionof a layer of a finished ski. Fig. 4 is an edgewise view of a ski, andFig. 5 shows the various composite parts of said ski in their mutualrelationship by way of diagrammatic representation. Fig. 6 is an endwiseview of a blank block,

According to the invention, the block I is produced by placing a numberof vertically bent boards 2 of the same or different species of wood ontop of each other and by gluing the boards together in this position,the block thus produced having imparted thereto a longitudinal shapesuch as to produce the desired bottom curvature of the finished ski. Theblock I is then cut on the dashed lines in Fig. l at right angles to thegluing surfaces into boards 3 extending in the longitudinal direction ofthe block I, the plane sides of the central board 3a being milled out insuch manner that, the board will be thinned, that is to say curvedinwardly at the center djas shown in Fig. 2. The boards 3 are againglued together with the board 3a provided with two inwardly curved sideslying at the center, into a block 5, which consequently will also obtaininwardly curved sides, whereupon two boards 6 consisting of aparticularly hard species of wood are glued onto the inwardlycurvedsides, said boards 6 having been cut out from a block constitutedand formed the same as the block I. The block 5 is out along a curvedline to form a board 1 the edges of which consist of harder species ofwood than the central portion of the board, and the shape of whichcorresponds approximately to the lateral and longitudinal form of thefinished ski.

For the construction and shaping of the ski, the board I is now planedin such manner that the same becomes about twice as thick at the centeras at the end portions, whereupon two wedge-shaped boards 8 are sawn outfrom a block constituted and formed in the same manner as the block I,said boards 8 being then gluedonto the upper sides of the thinned endportionsof the board I with their thinned ends turned toward the centerof the board 1. Now, the board 1 and the boards 8 constitute a singleboard serving as a sole for a ski. Now, a board 9 arcuately bent andhaving thinned ends is glued onto the upper side of the sole 1, 8, saidboard 9 being shorter than the sole 1, 8 and having been cut out from aspecial block prepared in the same manner as the blank block 5. Thisboard will form an upper layer of the finished ski H], whichconsequently will consist substantially of a lower board and an upperboard.

Now, wedg pieces II are inserted in known manner into the end portionsof the ski blank to reinforce the same, whereupon it is formed into aski.

It appears from Fig. 6 that in this manufacture of a ski the portion l2produced in the ski blank through the annual rings extends in thetransverse direction of the lower plate, which is of particularly greatimportance in the manufacture of a ski, inasmuch as comparatively deepgrooves will, as is well known, be produced in the sliding surface ofthe ski after the latter has been worn for some time.

In regard to the present manufacturing method it is to be noted thatupon the cutting and regluing of the blank block a better equalizationof the stresses or tensions is obtained in the lateral direction of theblock when, for instance, both sides of the central board 3a areinwardly curved than when only one side of said board is inwardlycurved.

It will appear from Fig. 5 that, a saving of material is obtained in theconstruction of the ski itself, inasmuch as the upper board 9 as well asthe wedge-shaped boards I, 8 may be taken out of blocks shorter than thelength of the whole ski. Finally, it appears from said figure thatretention of the desired longitudinal curvature of the ski is insured byreason of the fact that the lower board is composed of the arcuatelybent board 1 and of the wedge-shaped boards 8' glued onto the uppersides of the board.

What we claim is:

1. Method of manufacturing a ski with a ten sion are as permanent aspossible by the preparation of arcuate blocks, out of which blanks aresawn out, which are then worked into a ski, a number of vertically bentboards of the same or different species of wood being placed with theirbroad sides on top of each other and glued to- 3 gether into a blockhaving a tension arc corresponding to the tension arc of the finishedski, said glued block being cut up at right angles to the gluingsurfaces into central and side sheets in the longitudinal direction ofthe block and the plane sides of the central sheet only being recessedso as to make said sheet narrower at the center thereof, the side sheetsbeing glued to the a central sheet to form a blank block curved inwardlyfrom both sides at the center thereof, from which a board having atension arc corresponding to the tension arc of a ski and adapted,

for instance, to form the lower layer of the ski is cut out arcuately,an arcuately bent sheet being then glued onto said board to form theupper layer of the ski, said sheet having been cut out from a, blockcomposed of boards.

2. A method as claimed in claim 1, wherein the board forming the lowerlayer is shaped, prior to being glued onto the upper layer, in amannersuch as to become about twice as thick at the HENRYLUDWIGPETTERSSON. SVEN IVAN SELANGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Ullevoldsaeter Mar. 22, 19382,369,004 Andreff -a Feb. 6, 1945 Anderson Apr. 28, 1936

